黑毛皮蠹线粒体基因组分析及皮蠹科系统发育分析

Analysis of the mitochondrial genome of Attagenus unicolor japonicus ( Coleoptera: Dermestidae) and a phylogenetic analysis of Dermestidae

【目的】分析黑毛皮蠹Attagenus unicolor japonicus的线粒体基因组结构及皮蠹科的系统发育。【方法】本研究利用下一代测序方法测定了黑毛皮蠹的近完全线粒体基因组序列,并基于39种昆虫的cox1基因序列,通过最大似然法和贝叶斯法构建了皮蠹科的系统发育树。【结果】黑毛皮蠹线粒体基因组包含37个基因(2个rRNA基因,22个tRNA基因,13个蛋白质编码基因)和一段不完全的控制区,总长度为14 793 bp(GenBank登录号:MG017450)。基因排列顺序与已经发表的大多数昆虫线粒体基因组相同,不具有基因重排现象。13个蛋白质编码基因中除nad1和nad2之外其他基因的起始密码子均是典型的ATN,而nad1和nad2推断的起始密码子是TTG;除cox2,nad5及nad6基因终止密码子为不完全的终止密码子T外,其他蛋白质编码基因的终止密码子是典型的TAA或TAG。除了trnS1之外,所有的tRNAs均可形成典型的三叶草结构,trnS1缺少DHU臂而形成了一个简单的环,不能形成稳定的三叶草结构。trnS1的反密码子变成了UCU,而不是更常见的GCU。16S rRNA的二级结构包括5个结构域(第Ⅰ,Ⅱ,Ⅳ,Ⅴ和Ⅵ结构域),第Ⅲ结构域普遍缺失而变成一条单一的核苷酸链连接第Ⅱ和第Ⅳ结构域,共44个螺旋。12S rRNA的二级结构包括4个结构域,共27个螺旋,其中螺旋H47序列变异性较高,由一个长茎和一个大环组成。系统发育分析结果显示,皮蠹科内亚科级别的系统发育关系为:((长皮蠹亚科(Megatominae)+毛皮蠹亚科(Attageninae))+皮蠹亚科(Dermestinae))。【结论】皮蠹亚科(Dermestinae)、皮蠹属Dermestes及圆皮蠹属Anthrenus均为单系群,斑皮蠹属Trogoderma为多系群。皮蠹亚科Dermestinae和皮蠹科剩余的类群构成姐妹群。

【Aim】To analyze the mitochondrial genome of Attagenus unicolor japonicas and the phylogeny of Dermestidae. 【Methods 】 The nearly complete mitochondrial genome of A. unicolor japonicus was sequenced by next-generation sequencing（ NGS） method,and the phylogenetic trees were constructed using maximum likelihood method and Bayesian inference based on cox1 gene sequences of 39 insect species. 【Results】The mitochondrial genome of A. unicolor japonicus contains 37 genes（ 2 ribosomal RNA genes,22 tRNA genes and 13 protein-coding genes） and a partial control region,with the length of14 793 bp（ GenBank accession no. ： MG017450）. No gene rearrangement occurs in the genomeorganization of this insect,like most Coleoptera mitogenomes published. All protein-coding genes have typical start codon ATN except for nad1 and nad2,which start with the putative start codon TTG. cox2,nad5 and nad6 genes adjacent to the tRNAs terminate with T,while the other protein-coding genes stop with the typical stop codon TAA/TAG. The secondary structures of all tRNAs are of typical cloverleaf structure,except that of trnS1,in which the dihydrouracil arm（ DHU arm） can not form a stable stemloop structure but forms a simple loop. In addition,the anticodon for trnS1 is UCU rather than the usual GCU. The secondary structure of 16 S rRNA contains five domains（ domain Ⅰ,Ⅱ,Ⅳ,Ⅴ and Ⅵ） but lacks domain Ⅲ,with 44 helixes in total. The secondary structure of 12 S rRNA consists of four domains and 27 helixes. The helix H47 is a highly variable region,which composes of a long stem and a big loop.The results of phylogenetic analysis showed that the relationship of Dermestidae subfamilies is（（ Megatominae ＋ Attageninae） ＋ Dermestinae）. 【Conclusion】Dermestinae,Dermestes and Anthrenus are all monophyletic,while Trogoderma is polyphyletic. Dermestes is a sister group to the rest of Dermestidae.